The word dither -- evidently, the term dithering originally referred to a trembling or erratic movement, from the Middle English didderen, meaning "to tremble."

further, the halftone technique developed in the 1880s by Georg Meisenbach — breaking images into dots to simulate shades of gray — was called autotype, not dithering. The term dithering was later adopted in digital imaging and computing, particularly in the 1960s, when engineers applied the concept of adding noise to reduce color banding.